The synthesis, subcellular handling, compartmentalization, and differential release of stored and newly synthesized GH and Prl are to be investigated using specific immunoprecipitation and rat pituitary in perifusion. Special models will include hormone secreting pituitary tumors, non-euthyroid, antenatal and neonatal animals. The purpose of the studies is to identify pathways of subcellular hormone metabolism and specific branch points of those pathways with the aim of understanding the mechanisms by which physiologic and pharmacologic secretagogues alter hormone synthesis and release. It is anticipated that this information will be of use in the explanation of disease states and the identification of points at which the hormone secretory manifestations of these disease states might be subject to pharmacologic manipulation. Specifically the effects of endogenous and exogenous cyclic AMP, cyclic CMP, somatostatin, calcium, calcium ionosphores, prostaglandins, potassium, TRH, dopamine, protein synthesis inhibitors, intracellular protein transport inhibitors, and products of in vitro stimulation of rat hypothalamic are under investigation. The effects of these agents are being compared to a model of intracellular hormone compartmentalization which has been developed.